Showing papers in "Acta Anaesthesiologica Scandinavica in 1975"

Arterial hypotension and hypoxaemia during total hip replacement: the importance of thromboplastic products, fat embolism and acrylic monomers.

Abstract: Thirteen patients submitted to total hip replacement surgery by the Charnley technique were studied. Operations were performed under epidural analgesia with the patients awake and breathing air. During the surgical procedure, the magnitude of tissue-thromboplastic activity, the amount of fat globules, the presence of bone marrow cells and the concentrations of acrylic monomers were determined in the pulmonary arterial blood. Simultaneously, arterial blood gases and blood pressure were monitored. Marked reductions of the arterial blood pressure and arterial oxygen tension occurred after impaction of the femoral prosthesis, and minor depressions appeared after insertion of the acetabular prosthesis. A significant correlation was found between the release of tissue-thromboplastic products into the pulmonary circulation, i.e., products that initiate intravascular coagulation and the circulatory and respiratory reactions. The pulmonary fat droplets, per se, seem to be of minor importance, and the release of acrylic monomers is probably of no importance for these reactions. ZUSAMMENFASSUNG 13 Patienten, bei denen ein totaler Huftgelenksersatz nach Charnley durchgefuhrt wurde, dienten als Grundlage dieser Stuide. Die Operationen erfolgten in Epiduralanaesthesie, die Patienten waren wach und atmeten Luft. Wahrend des Eingriffes wurden das Ausmas der thromboplastischen Gewebsaktivitat, die Menge der Fett-trofchen, das Vorhandensein von Knochenmarkszellen und die Konzentration der Akrylmonomeren kontinuierlich im Pulmonalarterienblut bestimmt. Gleichzeitig wurden arterielle Blutgase und Blutdruck registrert. Nach dem Einzementieren der Femoralprothese kam er reglmasig zu ausgepragter Atem- und Kreislauf-depression, nach Einsetzen der Azetabularprothese traten geringere Dampfungen afu. Als Resultat unserer Untersuchungen steht fest, das die zirkulatorischen und respiratorischen Phanomene hauptsachlich durch die Freisetzung gewebsthrombopulasticher Produkte in dne Kreislauf verursacht werden, namlich Produkte, die zu intravaskularer Koagulation (Aggregation von Thrombozyten und Fibrin) fuhren. Die Fett-trofchen an sich sind von geringer Bedeutung, die Freisetzung von Akrylmonomeren wahrscheinlich irrelevant.

The Effect of Phenobarbitone Anaesthesia on Blood Flow and Oxygen Consumption in the Rat Brain

Abstract: The influence of phenobarbitone anesthesia on blood flow (CBF) and oxygen consumption (GMRO2) was evaluated in the rat brain, using a method that quantitatively measures CBF in mainly cortical areas. The data were compared to those obtained in animals under fentanyl citrate analgesia. Body temperature and arterial CO2 tension were maintained close to normal values in all groups. With 50 mg/kg of phenobarbitone, CBF and CMRO2 were reduced by about 20%. With 150 or 250 mg/kg, further reductions in CBF and CMRO2 were observed. At 250 mg/kg, CBF was reduced to one third, and CMRO2 to about 50% of normal. The results suggest that little further reduction in CBF or CMRO2 can be expected if the dose of phenobarbitone is increased above 250 mg/kg.

A Rational Approach to Dosage and Preparation of Parenteral Glucocorticoid Substitution Therapy During Surgical Procedures

Abstract: A rational, physiological schedule for parenteral glucocorticoid substitution therapy during surgical procedures is proposed based on the principle of imitating the normal hypothalamic-pituitary-adrenocortical response to surgery. The schedule includes the injection of 25 mg cortisol intravenously in all patients together with induction of anaesthesia. Following major surgery, 100 mg cortisol dissolved in saline or glucose is continuously infused intravenously every 24 hours until gastrointestinal function permits oral intake of usual glucocorticoid substitution therapy. In case continuous cortisol infusion is undesirable, 25 mg cortisol is injected intravenously every four hours. Following minor surgery, usual oral glucocorticoid therapy is started immediately after the operation. It is recommended to use water-soluble cortisol preparations and not cortisone acetate, which results in limited plasma cortisol levels. ZUSAMMENFASSUNG Es wird ein rationelles, physiologisches Schema fur die parenterale Glukokortikoid-Substitutionstherapie vorgeschlagen, das auf dem Prinzip beruht, die normale hypothalamisch-hypophysar-adrenocorticale Reaktion auf die Operation nachzuahmen. Zusammen mit der Anaesthesie-Einleitung erhalten alle Patienten 25 mg Cortisol i.v. Nach grosen Eingriffen werden uber 24 Stunden 100 mg Cortisol, in Glukose- oder Kochsalzlosung aufgelost, als i.v. Tropfinfusion verabreicht, bis die Magen-Darm-Tatigkeit eine orale Gluko-Kortikoid-Substitutions-therapie gestattet. Fur den Fall, das die kontinuierliche Zufuhr von Cortisol unerwunscht sein sollte, werden 25 mg Cortisol alle 6 Stnnden i.v. injiziert. Nach kleinen operativen Eingriffen kann ublicherweise schon unmittelbar anschliesend die Cortisoltherapie oral begonnen werden. Es wird empfohlen, wasserlosliche Cortisol-Praparate und nicht Cortison-Acetate zu verwenden, mit denen nur beschrankte Plasma-Cortisol-Spiegel erzielt werden konnen.

A comparison between measured and calculated changes in the lung function after operation for pulmonary cancer.

Abstract: Eighteen patients operated on for pulmonary cancer, the procedure varying from the removal of two segments to pneumonectomy, were subjected to measurement of the spirometric values VC, FEV1, FRC and RV preoperatively and 2–3 months postoperatively. The possibility of predicting the post-operative values from the number of segments removed was studied, partly with standard percentages (5.26%) per segment (method I), and partly with a percentage per segment in the affected area, calculated from the preoperative regional lung function tests using 133xenon. This latter test was carried out with a mobile apparatus using four detectors with tubular colimators and from the anterior surface of the thorax. Both methods of calculation gave, for the material as a whole, good agreement between the postoperative (measured) and the calculated values. However, with regard to certain patients, the regional lung function tests gave important information on preoperative reduced function in the affected area. In these patients, method No. II was by far the best for prediction of the postoperative values.

Effects of Thiopental (Trapanal®) on Coronary Blood Flow and Myocardial Metabolism in Man

Abstract: The influence of thiopental (Trapanal®) on coronary blood flow (MBF), myocardial oxygen consumption (MVO2), and general haemodynamics was investigated in seven patients without heart disease. Besides measurement of MBF, the amount of substrates (glucose, lactate, pyruvate and free fatty acids (FFA)) was also determined in arterial and coronary sinus blood samples. Thiopental was given intravenously in a mean dose of 4 mg/kg b.w. MBF was measured by means of the argon method. After injection of thiopental, all seven patients showed a significant increase of MBF and MVO2, a fact which can essentially be explained by the increase of heart rate. The effects of thiopental on arterial concentrations, arterio-coronary substrate differences, myocardial uptake, and O2-extraction ratio of the different substrates are discussed. ZUSAMMENFASSUNG Die Veranderungen der Koronardurchbluting, des myokardialen O2-Verbrauches, der allgemeinen Hamodynamik sowie der wichtigsten Substrate des Herzstoffwechsels unter dem Einflus von Thiopental wurden an insgesamt 7 herzgesunden Patienten untersucht. Die verabreichte i.v., Dosis von Thiopental betrug 4 mg/kg Korpergewicht. Die Koronardurchblutng wurde mittles der Argon-Fremdgasmethode bestimmt. Nach Injektion von Thiopental in der angegebenen Dosierung kam es bei allen Patienten zu einem signifikanten Anstieg desMBF und des MVO2, eine Tatsache, die im wesentlichen mit der Herzfrequenzsteigerung erklart werden kann. Der Einfluss von Thiopental auf die arteriellen Substratkonzentrationen, auf die Substrataufnahme und Sauerstoffextraktionsquotienten werden diskutiert.

Complications to tracheostomy and long-term intubation: a follow-up study.

Abstract: Hospital records of 79 patients treated with tracheostomy or long-term intubation from 1969 to 1971 were reviewed, and the 43 surviving patients were examined by laryngoscopy, x-ray and spirometry for complications subsequent to these treatments Early complications included one tube occlusion and one case of postextubation stridor in each group, one dislocated tube, one bilateral pneumothorax, and one case of fatal innominate arterial hemorrhage in the tracheostomy group, and two cases of atelectasis in the long-term intubation group Necropsy findings included necrotic ulcers in the larynx of intubated patients and eroded tracheal mucosa in both groups Late complications in surviving patients were prolonged hoarseness in six patients treated with prolonged intubation, two of whom had also had tracheostomy Radiologically verified tracheal stenosis (40-60%), four at the stoma level and one at the cuff level, all occurred in the tracheostomy group

Tricyclic antidepressive poisoning with special reference to cardiac complications.

Abstract: Sixty-eight cases of tricyclic antidepressive (TCA) poisoning are discussed. Cardiac arrest occurred in 8 patients, preceded by minor ECG-abnormalities. Five patients died. All cardiac arrests arose within the first 24 h after TCA ingestion. Fifty-seven patients developed ECG-abnormalities, of which 84% began within the first 6 h after TCA ingestion. ECG-abnormalities and other symptoms (respiratory arrest, coma, convulsion and hypotension) often occurred in the same patients. Treatment is described, and cardiac monitoring for at least the first 24 h is recommended. In cases of severe cardiac (ECG) abnormalities, monitoring is recommended until no ECG abnormalities are observed for at least 12 h. In conclusion, the unrestricted use of TCA is cautioned against, since TCA must be regarded as potentially cardiotoxic.

Pulmonary and circulatory reactions during total hip replacement surgery.

Abstract: The pulmonary and circulatory reactions to insertion of the acetabular and of the femoral prosthesis were studied during total hip replacement surgery in 22 patients with osteoarthrosis. The patients were given lumbar epidural analgesia and were divided into two groups. One group of 15 awake patients breathed air spontaneously (group A). The other group of seven patients received additional anaesthesia with controlled ventilation with air (group B). This permitted an evaluation of the influence of the ventilatory pattern on the pulmonary and circulatory reactions to the surgical events. The greatest alterations were observed following impaction of the femoral prosthesis. This event caused the following statistically significant changes in both groups: An increase in total pulmonary venous admixture (from a mean value of 6.8 to 12.2% in group A and from 8.2 to 10.5% in group B) and a decrease in arterial oxygen tension (group A: 80.3 to 71.5 mmHg; group B: 82.6 to 76.9 mmHg); an increase in pulmonary vascular resistance (group A: 122 to 155 dyn · s · cm-5; group B: 129 to 164 dyn · s · cm-5) and an increase in mean pulmonary arterial pressure (group A: 17.3 to 19.0 mmHg; group B: 21.8 to 24.4 mmHg). Furthermore, within the first 2 min after impaction a distinct transient rise in mean pulmonary arterial pressure by 2–4 mmHg was noted in a few patients, and in many patients the mean systemic arterial pressure decreased by 5 mmHg or more. No significant changes were found in cardiac output, pulmonary capillary wedge pressure, oxygen uptake, mixed venous oxygen tension, acid-base values, ratio of total dead space to tidal volume, or total airway resistance. The above findings indicate a tendency to pulmonary vascular and peripheral airway constriction leading to transient ventilation/perfusion disturbances and a decrease in arterial oxygen tension, and peripheral vasodilatation leading to a transient decrease in systemic arterial pressure. ZUSAMMENFASSUNG Die pulmonalen und zirkulatorischen Keaktionen auf das Einsetzen von Azetabulum- bzw. Femurkopf-Prothesen wurden bei 22 Patienten mit Osteoarthrosen wahrend totaler Huftgelenksersatz-Operationen untersucht. Die Patienten bekamen eine lumbale Epidural-anaesthesie und wurden in zwei Gruppen unterteilt. Gruppe A (15 wache Patienten) atmete spontan Luft, Gruppe B (7 Patienten) bekam eine Zusatznarkose und wurde mit Luft kontrolliert beatmet. Dies erlaubte eine Auswertung des Einflusses des Ventilationsmusters auf die pulmonalen und zirkulatorischen Reaktionen im Verlauf der Operation. Die deutlichsten Anderungen wurdeu nach dem Einsetzen der Femurprothese beobachtet. In beiden Gruppen wurden dadurch die folgenden statistisch signifikanten Anderungen bewirkt: Ein Ansteigen der gesamten pulmonalen venosen Beimengung (von einem Mittelwert von 6,8 auf 12,2%, in Gruppe A und von 8,2 auf l0,5% in Gruppe B) und eine Abnahme der arteriellen Sauerstoffspannung (Gruppe A: von 8O,3 auf 71,5 mmHg; Gruppe B: von 82,6 auf 76,9 mmHg); ferner ein Ansteigen des pulmonalen Gefaswiderstandes (Gruppe A: von 122 auf 155 dyn·s·cm−5; Gruppe B: von 129 auf 164dyn·s·cm−5) und eine Zunahme des Druckes in der A. pulmonalis (Gruppe A: von 17,3 auf 19.0 mmHg; Gruppe B: von 21,8 auf 24,4 mmHg). Weiters wurde innerhalb der ersten zwei Minuten nach dem Einsetzen der Prothese ein deutlicher vorubergehender Anstieg des mittleren Pulmonalarteriendruckes um 2-4 mmHg bei einigcn Patienten festgestellt sowie bei vielen Patienten cine Abnahme des arteriellen Mitteldrucks im grosen Kreislauf um mmHg oder mehr. Nicht-signifikante Veranderungen boten das HMV, der pulmonal-kapillare Keildruck, die 02-Aufnahme, die gemischt-venose Sauerstoffspannung, die Saure-Basen-Werte, die Relation zwischen Totraum und AZV sowie der Gesamtwiderstand der Atemwege. Die genannten Befunde weisen auf cine Tendenz zur Verengung des pulmonalen Gefasbettes und der peripheren Atemwege hin, sowie auf vorubergehende Storungen der Ventilation/Perfusion, eine Abnahme der arteriellen Sauerstoffspannung und auf eine periphere Vasodilatation hin, die zu einem passageren Sinken des arteriellen Systemdruckes fuhrt.

Effect of controlled halothane anaesthesia on splanchnic blood flow and cardiac output in the dog.

Abstract: Effects of halothane anaesthesia on splanchnic blood flow and cardiac output were studied in six dogs. Blood flows in the hepatic artery, the superior mesenteric artery and the portal vein were measured electromagnetically. Cardiac output was measured by thermodilution. Depth of anaesthesia, ventilation, acid–base state and body temperature were controlled. Cardiac output and blood flows in the hepatic artery, the superior mesenteric artery and the portal vein decreased significantly to 73%, 54%, 59% and 60% of control values, respectively. Total peripheral vascular resistance decreased significantly, while mesenteric and portal resistance remained essentially unchanged and hepatic arterial resistance showed a significant increase. It is suggested that the difference between the various vascular responses may be caused by a differentiated release from baroreceptor inhibition in various parts of the bulbar vasomotor center. ZUSAMMENFASSUNG Die Auswirkung von Halothannarkose auf die Splanchnikusdurchblutung und den Cardiac Output wurden bei 6 Hunden untersucht. Die Durchblutung der Arteria Hepatica, der Mesenterica Superior und der Pfortader wurden elektromagnetisch gemessen. Cardiac output wurde mittels Thermodilution registriert. Narkosetiefe, Atmung, Saure-Basen-Verhaltnis und Korpertemperatur wurden uberwacht. Cardiac output und die Durchblutung der Arteria Hepatica, der Mesenterica Superior und der Pfortader waren signifikant auf 73%, 54%, 59% und 60% der Kontrollwerte herab gesetzt. Totaler peripherer GefaBwiderstand nahm ebenfalls signifikant ab. Wahrend mesenterialer und portaler Widerstand im Wesentlichen unverandert blieben und der Widerstand der Arteria Hepatica einen signifikanten Anstieg zeigte. Es wird angenommen, daB die Unterschiede zwischen den verschiedenen Reaktionen der GefaBgebiete durch differenzierte Freisetzung von Barorezeptoreninhibition in den verschiedenen Teilen des bulbaren Vasomotorenzen trums bewirkt werden.

High-frequency positive-pressure ventilation (hfppv) during transthoracic resection of tracheal stenosis and during peroperative bronchoscopic examination.

Abstract: Operation of a patient with intrathoracic tracheal stenosis using a new ventilation technique (HFPPV) is described. The technique permits tracheoscopy during ventilation and operation, thus enabling exact location of the stenosis to be obtained. Further, peroperative tracheoscopic checking of the anastomosis can be carried out. Resection and anastomosis can be performed without interference of a bulky endotracheal tube.

Metabolic changes in the cerebral cortex of the rat induced by intravenous pentothalsodium.

Abstract: The effects of thiopental on cerebral metabolism were evaluated by means of measurements of cerebral metabolic rate for oxygen (CMRo2) and of tissue levels of organic phosphates, glycolytic substrates, citric acid cycle intermediates and selected amino acids. Shortly after the beginning of thiopental administration, CMRo2 was reduced to half the normal value, and there were signs of retardation of glycolytic flux at the phosphofructokinase step. Inhibition at this regulatory enzymatic step could be related to an increase in phosphocreatine and a fall in inorganic phosphate concentration. The rise in phosphocreatine, and the unchanged levels of ATP, ADP and AMP demonstrate that induction of anaesthesia with thiopental is unrelated to energy failure. Changes in citric acid intermediates included a fall in malate, and probably also in citrate, α-ketoglutarate and fumarate, with a tendency towards reduction in the pool of citric acid cycle intermediates; and the amino acid changes were dominated by a progressive rise in aspartate. It is suggested that these changes are secondary to a reduced rate of pyruvate delivery, and to a decrease in malate/oxaloacetate ratio.

Cardiorespiratory function during thoracic anaesthesia: a comparison of two-lung ventilation and one-lung ventilation with and without PEEP5.

Abstract: Previous studies have shown that, in patients undergoing thoracic surgery, a relatively high positive end-expiratory pressure (PEEP of 10 cmH2O = PEEP10) has no beneficial effect on oxygenation during one-lung ventilation (OLV). In the present investigation, cardiorespiratory function was examined in 11 patients intubated endobronchially and undergoing thoracotomy. Comparison was made between two-lung ventilation (TLV) and OLV and between zero end-expiratory pressure and PEEP5 during OLV. Cardiac output was determined to obtain information of the total oxygen delivery (cardiac output times arterial O2 content. The change from TLV to OLV was accompanied by a marked fall in PaO2 and a marked rise in shunt, whereas no significant change was observed in mean cardiac output. Oxygen delivery also remained unchanged due to relatively small decrease in SaO2 (arterial oxygen saturation) and maintenance of cardiac output. The application of PEEP5 during OLV produced no significant changes in these parameters. The findings in individual patients demonstrated the relative importance of cardiac output in determining oxygen delivery during OLV. A significant negative correlation was found between inspiratory airway pressure and cardiac index during OLV.

Effects of hypothermia and hyperthermia on brain energy metabolism.

Abstract: The influence of elevated and reduced body temperatures upon the metabolic state of the brain was evaluated from the tissue concentrations of phosphocreatine (PCr) ATP, ADP and AMP and from the concentrations of glucose, lactate and pyruvate in immobilized and artificially ventilated rats anesthetized with 70% N2O. The results were compared to the results obtained in normothermic animals. It was found that rats with body temperatures of 32 degrees and 22 degrees C had the same brain tissue concentrations of high energy phosphates and the same adenylate energy charge as the controls, but hypothermia led to a progressive decrease of both cerebral and arterial lactate and pyruvate concentrations. A metabolic acidosis but no excess lactate appeared in the blood. At a body temperature of 42 degrees C, the metabolic pattern in the brain agreed with a state of hypoxia at a time when there was no sign of substrate depletion. Arterial blood showed excess lactate which may indicate an inadequacy of the oxygen supply also to other tissues.

Serum Cholinesterase Activity in Burned Patients. II: Anaesthesia, Suxamethonium and Hyperkalaemia

Abstract: The importance of serum cholinesterase activity in burned patients was evaluated in relation to anaesthesia. Anaesthesia included a repeated administration of suxamethonium. Thirty–two patients with an estimated area of burn between 3 and 72% were studied during 39 anaesthetic procedures. A statistically significant inverse correlation was found between serum cholinesterase activity and the apnoea period following intravenous suxamethonium. In patients with very low enzyme activity, apnoea periods of 10 to 25 min were observed. No correlation was found between the changes in serum potassium following suxamethonium and either the serum cholinesterase activity or the changes in Pco2 and pH. The most reliable parameters in predicting a dangerous increase in serum potassium following intravenous suxamethonium were shown to be 1) the time elapsed from burn injury to anesthesia and 2) the degree of burn injury. However, abnormal reactions to suxamethonium were seen as early as 9 days following injury, and rises in serum potassium to over 6 mmol/1 were observed even in patients with a total burn surface of around 8%, i.e., less than the surface of one arm. ZUSAMMENFASSUNG Die Bedeutung der Serum-Cholinesterase-Aktivitat bei Verbrennungspatienten wurde in Verbindung mit einer Anaesthesie bewertet, bei der es zu wiederholter Verabreichung von Suxamethonium kam. 32 Patienten mit 3-72% Verhrennungen ihrer Korperoherflache wurden wahrend 39 Narkosen untersucht. Eine statistisch signifikante reziproke Relation wurde zwischen der Serum-Cholinesterase-Aktivitat und der Apnoezeit nach i.v. verabreichtem Suxamethonium gefunden. Bei Patienten mit sehr niedriger Enzymaktivitat wurden Apnoezeiten von 10-25 Minuten beobachtet. Keine Korrelation wurde gefunden zwischen den Veranderungen des Serum-Kaliums nach Suxamethonium und entweder der Serum-Cholinesterase-Aktivitat oder Pco2- und pH-Veranderungen. Als verlaslichste Parameter fur die Vorhersage eines gefahrlichen Serum-K-Anstieges nach i.v. Suxamethonium erwiesen sich 1. das Zeitintervall zwischen der Brandverletzung und der Anaesthesie und 2. der Grad der Verbrennung. Allerdings wurden abnorme Reaktionen auf Suxamethonium auch bereits am 9. Tag nach der Verletzung gesehen und Anstiege des Serum-K auf uber 6 meg/h wurden sogar schon bei Patienten beobachtet, bei denen nur 8% der Korperoberflache, das ist weniger als die Oberflache eines Armes, verbrannt waren.

Evaluation of Impedance Cardiography as a Non‐Invasive Means of Measuring Systolic Time Intervals and Cardiac Output

Abstract: Impedance cardiography was used for non-invasive determinations of systolic time intervals (STI) and cardiac output. The results were compared with simultaneously obtained invasive measurements of STI from central aortic pressure curves and of cardiac output using the dye-dilution technique. The study was performed on eight dogs during increasing halothane concentration. A close correlation was found between non-invasively and invasively measured left ventricular ejection time = LVET (r = 0.986) and pre-ejection period - PEP (r - 0.948). Measurements of cardiac output derived from changes in thoracic impedance were determined 1) using a fixed value of p (p - the resistivity of blood) and 2) using an individual value of p based on the actual hematocrits. When compared to cardiac outputs obtained by dye-dilution the correlation coefficients were r = 0.806 and r = 0.816, respectively. Impedance cardiography is a useful method of evaluating changes in cardiac output. The method permits simultaneous observations of changes in STI and cardiac output as an index of cardiac function.

Electroencephalographic activity in children under enflurane anesthesia.

Abstract: EEG, end-tidal CO2, neck muscle EMG, eye movements, and ECG were recorded in 17 children undergoing enflurane anesthesia combined with N2O and O2. All subjects were classified in the lowest risk group and had normal pre-anesthetic EEG recordings. Eleven subjects were breathing spontaneously and six were under controlled ventilation. Thirteen subjects were hyperventilated for short periods. As previously reported for adults, various signs of increased central nervous excitability appeared. At the enflurane concentration of 4% all three cases with Paco2 below 32 mmHg showed generalized high voltage epileptic activity of grand mal type followed by several minutes of postictal slowing. One of these subjects also showed motor manifestations of the electrographic seizure activity. At 3% enflurane, three out of eight subjects showed electrographic seizure activity of poly-spike-suppression type. One of these children also had motor manifestations during this type of seizure activity at a Paco2 of 31 mmHg. The results indicate that electrographic seizure activity is common among children with moderate hypocapnia at enflurane concentrations of 3% or more. ZUSAMMENFASSUNG EEG, Endexspirations-CO2 Nackenmuskel-EMG, Augenhewegungen und EKG wurden bei 17 Kindern registriert, an denen eine kombinierte Enfluran-N20-02-Narkose vorgenommen wurde. Alle gehorten der niedrigsten Risikogruppe an und hatten normale pranarkotische EEG. Elf Versuchspersonen atmeten spontan, sechs wurden kontrolliert ventiliert. 13 Personen wurden fur kurze Perioden hyperventiliert. Wie bereits fruher bei Erwachsenen beschrieben, traten verschiedene Anzeichen einer erhohten zentral-nervosen Erregbarkeit auf. Bei 4% Enfluran-Konzentration zeigten alle drei Patienten mit einem Paco2 unter 32 mmHg generalisierte hochgespannte epileptische Aktivitat vom Typus des Grand-mal, gefolgt von einer mehrere Minuten andauernden postictalen Verlangsamung. Eine dieser Personen zeigte auch motorische Manifestationen dieser elektrographischen Krampfaktivitat. Bei 3% Enfluran zeigten 3 von 8 Personen elektrographische Krampfaktivitat vom Typus der Poly-Spike-Suppression. Auch von diesen Kindern hatte eines motorische Manifestationen wahrend dieses Typus der Krampfaktivitat hei einem Paco2 von 31 mmHg. Diese Ergebnisse weisen darauf hin, das elektrographische Krampaktivitat hei Kindern mit masiger Hypokapnie bei Enflurankonzentrationen von 3% und mehr nicht ungewohnlich ist.

Serum cholinesterase activity in burned patients. I: biochemical findings.

Abstract: The purpose of the study was to determine the magnitude and the aetiology of alterations in serum cholinesterase activity (pseudocholinesterase) in burned patients. Sixty burned patients with an estimated area of burn between 3 and 72% of body surface were investigated. Serum cholinesterase activity, serum albumin concentration and serum bilirubin were measured at various time intervals. The magnitude as well as the rate of fall of serum cholinesterase activity was found to be closely correlated with the severity of burn injury. Minimum levels were often reached 5 to 6 days after the burn injury, at which time the activity might have been depressed by more than 80 per cent. In the most severely burned patients, the activity sometimes remained low for months despite wound healing. Apart from the severity of the burn injury in the individual patient, several important factors determined the level of serum cholinesterase activity at a given time. These included the presence or absence of local or systemic infections, the event of recent surgery such as slough removal or skin grafting, and blood transfusions. The decrease in serum albumin concentration following the burn injury occurred earlier than the decrease in serum cholinesterase activity. Minimum levels were often reached during the first 24 h, after which time the concentration rose to reach fairly constant but decreased levels after 4 to 5 days. Apart from this initial phase, the changes in serum albumin concentration were roughly proportional to the changes in serum cholinesterase activity. The possible reasons for these findings are discussed.

Influence of changes in arterial PCO2 on cerebral blood flow and cerebral energy state during hypothermia in the rat.

Abstract: In order to study the relationship between arterial PCO2 and cerebral blood flow (CBF) in hypothermia, the body temperature of artifically ventilated rats was decreased to 22 degreesC, and changes in CBF were evaluated from arteriovenous differences in oxygen content (AVDO2) at PaCO2 values of 15, 30, 40 and 60 mm Hg. The results were compared to those obtained at normal body temperature (37 degrees C) over the PaCO2 range 15-60 mm Hg. Separate experiments were performed to evaluate CBF and CMRO2 at 22 degrees C and a PaCO2 of 15 mm Hg, using an inert gas technique for CBF. The tissue contents of phosphocreatine, ATP, ADP, AMP and lactate were measured in hypothermic animals at PaCO2 values of 15, 30 and 60 mm Hg. The results showed that changes in CBF were of the same relative magnitude in hypothermia and normothermia when PaCO2 was increased from about 35 to about 60 mm Hg. However, with a decrease in PaCO2 the reduction in CBF was much more pronounced in hypothermia, and at PaCO2 15 Mm Hg CBF was less then 20% of the value measured in normothermic and normocapnic animals. The results of the metabolite measurements gave no evidence of tissue hypoxia in spite of the pronounced reduction in CBF. Although the results demonstrate that the brain of a hypothermic animal is protected against the harmful effects of a lowered CBF, it may not warrant recommending hyperventilation in clinical cases of hypothermia, especially not in patients with arteriosclerosis or cerebrovascular diseases.

Single-Dose Intercostal Nerve Blocks with Etidocaine for Pain Relief after Upper Abdominal Surgery

Abstract: I t is well-known that significant decreases in dynamic spirometric parameters ( BROMACE 1955, RNSCOMBE 1957) and arterial oxygenation follow upper abdominal surgery ( TROELL 195 1, CARLSTEN et al. 1954, DIAMENT & PALMER 1966, BAY et al. 1968). Ventilation is restricted by irritation from the area of surgery (NUNN 1962) and is further depressed by anaesthetic and narcotic drugs (&BERT & BENDIXEN 1964). I t is assumed that an uneven ventilation perfusion distribution occurs due to shallow tidal volumes (GEORG et al. 1967). This may lead to increased alveolar shunting and impaired oxygenation. Underventilation of some areas may result in atelectasis and true pulmonary shunting of blood. Several studies confirm that epidural blocks ( SIMPSON et al. 1961, SPENCE & SMITH 1971, HOLMDAHL et al. 1972) and repeated intercostal blocks (STARR & GILMAN 1942, FINER 1970, BRIDENBAUGH et al. 1973) improve the ventilation. However, epidural blocks in the thoracic region are not without risks, and repeated intercostal blocks involve discomfort for the patient and are time-consuming for the anaesthetist. The hypothesis behind this study is that a single intercostal block by a long-acting local anaesthetic agent, given at the end of operation by preventing the initial formation of subclinical atelectasis, may maintain a better pulmonary function for the whole post-operative period. We assume that by preventing the mismatching of ventilation perfusion immediatcly after operation, the situation of true shunting of blood in the lung may not occur.

Mechanical ventilators as vehicles of infection.

Abstract: Twenty-five patients from the intensive care unit who had been subjected to tracheostomy and require mechanical respiration were studied. Data are presented concerning the bacteriological controls performed on the tracheal exudates, various parts of the ventilators (Engstrom Model 200 and Bennett PR-2), and the Wright spirometer. The germs found were mainly pseudomonas, enterobacteriaceae germs and bacteria from the acinetobacter group. There was a high incidence of infection in the tracheostomies of these patients. We found a cause and effect relationship between the contaminating bacteria isolated from the cannula and the bacteria isolated from the tracheal exudates in the case of pseudomonas aeruginosa. However, this was not found to be the case where enterobacteriaceae were concerned. Acinetobacter calcoaceticus were isolated almost exclusively in the ventilators. The study calls attention to the need for rigorous disinfection of ventilators to prevent hospital cross infections.

Postoperative hepatic blood flow and its relation to systemic circulation and blood gases during splanchnic blockade and fentanyl analgesia.

Abstract: Thirty-four patients with gallbladder disease, but otherwise healthy, were studied in connection with cholecystectomy. For postoperative analgesia, 22 patients were given a posterior splanchnic blockade with 0.5 % plain lidocaine, and 12 were injected intramuscularly with fentanyl in a dose of 3.5 ug/kg b.w. Postoperatively, before administration of the analgesic agent, the cardiac output, mean arterial blood pressure, heart work and estimated hepatic blood flow were increased and the total peripheral resistance, splanchnic vascular resistance, arterial oxygen tension and base excess values were decreased. Fentanyl in addition to its analgesic effect, also decreased the arterial oxygen tension and pH and increased the arterial carbon dioxide tension. There was little change in cardiac output, mean arterial blood pressure and estimated hepatic blood flow. Following splanchnic blockade, on the other hand, pain relief was accompanied by a decrease in cardiac output, mean arterial blood pressure and heart work to about the preoperative level, while the estimated hepatic blood flow remained unchanged and the splanchnic vascular resistance decreased rapidly. Neither total peripheral resistance nor blood gases altered as a result of splanchnic blockade.

Side Effects and Skills Related to Driving After Intramuscular Administration of Bupivacaine and Etidocaine

Abstract: Eleven healthy subjects were injected intramuscularly with a saline placebo, 1.3 mg/kg of 0.5% plain bupivacaine, or 2.6 mg/kg of 1.0% plain etidocaine in a double-blind cross-over fashion. Before and at 1/2, 2 and 4 hours after injection, side effects were recorded, and psychomotor skills related to driving were measured. Fatigue, dizziness, and sore thighs were significantly more common with etidocaine than with bupivacaine or the saline solution. Bupivacaine significantly impaired eye-hand coordination and flicker fusion discrimination during the whole observation period. Etidocaine impaired flicker fusion discrimination only. The subjects' adaption to darkness, sensitivity to brightness, and visual discrimination ability in bright counterlight remained unaltered after each treatment. The results suggest that such psychomotor performance as driving ability is impaired for at least 2 hours after a patient receives 1.3 mg/kg of plain bupivacaine or 2.6 mg/kg of plain etidocaine intramuscularly. /Author/

Effects on breathing mechanics and gas exchange of different inspiratory gas flow patterns during anaesthesia.

Abstract: Ten patients without known cardiac or respiratory disease were investigated with breathing mechanics and gas exchange studies during anaesthesia and artificial ventilation. The effects of three different inspiratory gas flow patterns, namely, accelerating, constant and decelerating flows were studied. A decelerating flow resulted in an increase of total compliance when compared to an accelerating or a constant flow. However, at the same time, there was an increase in physiological dead space and a decrease in alveolar ventilation with a decelerating flow compared to an accelerating flow. These results seem to indicate an improved gas distribution in the greater airways with a decelerating flow pattern, but when the total effects of gas exchange were judged, the greatest benefits were with an accelerating flow. ZUSAMMENFASSUNG An 10 Patienten ohne nachgewiesen Storungen der Herz- oder Lungenfunktion wurden in universeller Anaesthesie, bei Kunstlicher Beatmung, Untersuchungen des Gasaustausches undder Atmungsmechanik vogenommen. Wahrend der Inspirationsphase wurde die Wirkung dreier charakteristischer Formen der Gasstromung getestet: akzelerierende, konstante und dezeleriercnde Stromung. Dezelerierende Gasflow resultierete in enicm Anwachsen der Gesamtcompliance im Vergleich mit akzelerierender oder knostanter Stromung. Gleichzeitig erfolgte jedoch auch eine Vergrosserung des pysiologischen Totraumes und ein Abfall der alveolaren Ventilation bei Anwendung dezelerienden Gasstromes im Vergleich mit akzelerierendem. Dese Ergebnisse scheinen auf eine bessere Gasdistribution in den grosseren Luftwegen bei dezelerierender Stromung hinzudeuten, bei Betrachtung der Gesamtwirkung auf den Gasaustausch erwes eine akzelerierende Stromungscharakteristik sich jeodch als vorteilhafter.

Effects on breathing mechanics and gas exchange of different inspiratory gas flow patterns in patients undergoing respirator treatment.

Abstract: In order to investigate the importance of different inspiratory gas flow patterns in respirator treatment, eight intensive care patients were studied with breathing mechanics and five patients also with gas exchange studies. Three different inspiratory gas flow patterns were tested in randomized sequences namely, accelerating, constant and decelerating flow. All three flow patterns were generated by the same respirator. No end-inspiratory pause was used. The results point to a favourable effect on breathing mechanics of a decelerating and a constant flow when compared with an accelerating flow type. However, when the total effects on gas distribution and lung perfusion were evaluated in the gas exchange studies, no significant differences were seen between the three flow patterns. ZUSAMMENFASSUNG An 8 Patienten einer Intensivpflegestation wurden atmungsmechanische und bei 5 dieser 8 Patienten ausserdem Gasaustauschuntersuchungen ausgegfuhrt, um die Bedetung vershiedener Gasflowcharakteristica bei kunstlicher Beatumng wahrend der Inspiration zu erforschen. Drei verschiedene Arten der Gasstromung wurden wahrend der Innspiration in wikklurlicher Reihenfolge getestet: akzelerierende, konstante, und dezelerierende Stromung. Alledrei Stromungsarten urden mit dem gleichen Respirator erzeugt. Eine endinspiratorische Pause kam nicht zur Anwendung. Die Ergebnizsse deuten auf einen gunstigen Effekt von dezelerierenden und konstantem Flow auf die Atmungsmechanik hin. Bei der Bewertung der Gesamtwirkung dieser Flowcharakteristika auf die Gasverteilung und die Lungendurchblutung and Hand der Untersuchungen des Gasaustausches zeigte sich jedoch kein Unterschied zeischen den drei Stromungsarten.

The use of 125I-labelled fibrinogen for determination of fibrin trapping in the lungs in patients developing the microembolism syndrome.

Abstract: The microembolism syndrome occurred in four patients out of a series of 15 patients with multiple injuries who were considered to run a risk of developing this syndrome. These four patients showed signs of fibrin trapping in the lungs, as demonstrated by the use of 125I-labelled fibrinogen and external detection over the lungs. It is, therefore, considered that this method can be used for diagnosing the microembolism syndrome. The fibrin trapping occurred at the onset of the progressive respiratory insufficiency. The time relation between the uptake of fibrin and the onset of the progressive respiratory insufficiency supports the theory of a causal connection between fibrin and pulmonary damage. Measurements of different coagulation and fibrinolysis factors in the blood were not able to discriminate between patients who developed the microembolism syndrome and those who did not.

Effects of General Anaesthetics on the pH of Gastric Contents in Man During Surgery: A Survey of Halothane, Fluroxene and Cyclopropane Anaesthesia

Abstract: The effect of premedication and three general anaesthetics on gastric content pH was investigated. Neither premedication with pentobarbital-atropine nor morphine-scopolamine given 1–2 h prior to anaesthesia appeared to affect the acidity of the gastric contents. Halothane invariably increased the pH of the gastric contents; none of the seven patients studied had a gastric pH of less than 2.5 (mean5.1) after 1 h of anaesthesia. Cyclopropane uniformly maintained the acidity of the gastric contents; only one out of seven patients had a gastric content pH above 2.5 (mean 1.7) after 1 h of anaesthesia. This effect of cyclopropane in maintaining the pH of gastric contents was unaffected by the use of premedication and induction with thiopental. Fluroxene affected the pH of the gastric contents much less uniformly. Although the pH for the group as a whole gradually increased (after one hour from 1.7 ± 0.2 (s.e. mean) to 3.1 ± 0.7), some of the seven patients studied reacted to fluroxene with a constant low gastric content pH. The findings are discussed, and it is concluded that the risk of pulmonary complications in case of vomiting and aspiration upon emergence from anaesthesia is greater if the anaesthetic agent is cyclopropane or fluroxene, than if it is halothane. ZUSAMMENFASSUNG Es wurden die Auswirkunzen der Pramedikation und dreir Anaesthesiemitted auf das pH des Magensaftes untersucht. Weder eine Pentobarbital-Atropin- noch eine Morphin-Scopolamin-pramedikation, 1-2 Stunden vor Narkosebeginn averabreicht, schien die Magensaftaziditat zu beeinflussen. Halothan erhohte stets das pH des Magensaftes; keiner der 7 untersuchten Patienten hatte eine Stunde nach Narkosebginn ein pH von weniger als 2,5)im Durchschnitt 5,1). Zyklopropan hielt die Aziditat des Magensaftes gleichmasig aufrecht; nur einer von 7 Patienten hatte nach einer Stunde Narkose ein pH von mehr als 2,5 (im Durchschnitt 1,7). Diese aziditatserhaltende Wirkung des Zyklopropans blieb durhc die Pramedikation und die Thiopentaleinleitung unbeeinflus. Unter Fluroxin waren die pH-Veranderungen des Magensaftes weniger einheitlic. Obwohl das pH in dieser Gruppe im Ganzen gesehen allmahlich anstieg (innerhalb einer Stunde von 1,7 ± 0,2 auf 3,1 ± 0,7), reagierten einige der 7 untersuchten Patienten auf Fluroxin mit einem konstant neidrigen Magensaft-pH. Diese Befunde werden diskutiert und der Schlubs gezogen, das das Risiko von Lungenkomplikationen im Falle des Erbrechens und der Aspiration bein Erwachen aus der Narkose mit Zyklopropan oder Flurexin hoher ist als bei Halothan.

Effect of dihydroergotamine on perpheral circulation during epidural anaesthesia in man.

Abstract: The effect of intravenous administration of dihydroergotamine (DHE) on regional blood flow in the forearm and calf after pharmacological nerve blockade of the lower body induced by epidural anaesthesia has been studied in 13 subjects. After anaesthesia, DHE induced a significant increase in blood flow in the forearm with intact innervation and a significant decrease in blood flow in the nerve-blocked calf. On the average, the arterial blood pressure increased slightly. The calculated local vascular resistance increased in the nerve-blocked calf, probably due to a direct myogenic constrictive effect of DHE. In the intact forearm, local vascular resistance decreased. The results indicate that DHE exerts a complex effect on resistance vessels in addition to its well-known effect on the capacitance vessels.

Anesthesia for cesarean section II: effects of the induction-delivery interval on the respiratory adaptation of the newborn in elective cesarean section.

Abstract: Ten healthy mothers and their infants were studied in connection with elective cesarean section. Anesthesia was induced with 250–300 mg hexobarbitone followed by 100 mg succinylcholine for endotracheal intubation. The surgeon started the operation when the eyelid reflex disappeared, and delivered the baby as quickly as possible. Mean induction-delivery (I-D) interval was 2 min 45 s. Anesthesia was then deepened with further barbiturate, diazepam and methoxyflurane, and alcuronium used as muscle relaxant. The respiratory adaptation of the infant was studied by blood gas and acid-base measurements in repeated arterial samples during the first three hours of life. The mothers were interviewed after 3–12 months. A comparison was made with another barbiturate group with a longer I-D interval (x = 9 min 10 s). The present material showed initially higher Pao2 lower Paco2, higher pH and less base deficit (BD), which reflected the maternal state at delivery. After 10–30 min, the results approached equivalence, though the babies in the short I-D group showed a tendency toward normalization of metabolic acidosis earlier. At the interviews, two mothers complained of pain during skin incision, and two of nightmares. Anesthesia with barbiturate for cesarean section with the I-D intervals studied in both groups allowed good respiratory adaptation in the infants. There is, nevertheless, the need for an adequate period of time between induction and the start of the operation in order to minimize the risk for maternal awareness. ZUSAMMENFASSUNG Im Zusammenhang mit geplanten Kaiserschnittoperationen wurden 10 gesunde Mutter und deren Babies untersucht. Narkoseeinleitung erfolgte mit 250-300 mg Hexobarbitone (Evipan®) und anschliesend 100 mg Succinylcholin zur Vornahme der endotrachealen Intubation. Der Operateur machte den Hautschnitt beim Verschwinden des Lidreflexes und beendete die Entbindung so rasch wie moglich. Das durchschnittliche Einleitung-Geburts-Intervall war 2 min 45 s. Spater wurde die Narkose mit weilerem Barbiturat, Diazepam und Methoxyfluran vertieft und Alcuronium als Muskelrelaxans zugesetzt. Die Atrnungsanpassung der Neugeborenen wurde wahrend der drei ersten Lebensstunden mittels wiederholter arterieller Blutgas- und Saure-Basen-Bestimmungen untersucht. Die Mutter wurden nach 3-12 Monaten interviewed. Diese Serie wurde mit einer anderen Barbituratgruppe mit langerem Einleitungs-Geburts-Intervall (im Durchschnitt 9 min 10 s) verglichen. Die jetzige Gruppe zeigte zu Beginn einen huheren Pco2, einen niedrigeren Pco2 ein hoheres pH und geringeres Basendefizit (BD), den Zustand der Mutter zum Zeitpunkt der Geburt darstellend. Nach 10-30 Minuten waren die Ergebnisse beider Sericn ziemlich gleich, wobei die nach kurzen Intervallen entbundenen Babies die Tendenz zu rascherer Normalisierung ihrer metabolischen Azidosen zeigten. Bei den Interviews klagten zwei Mutter uber Schmerzen, die sie beim Hautschnitt verspurt hatten, zwei uber Alptraurne. Mit Barbituraten eingeleitete Allgemeinnarkosen fur Kaiserschnitt-entbindungen ermoglichten den Neugeborenen in beiden untersuchten Gruppen mit verschiedenen Einleitungs-Geburts-Intervallen eine gute Atemanpassung. Es besteht jedoch die Notwendigkeit, einen angemessenen Zeitraum zwischen Einleitung und Hautschnitt verstreichen zu lassen, um das Risiko des Wachseins zu reduzieren.

The Effect of Anesthesia on Intraoperative and Postoperative Bleeding during Abdominal Prostatectomies: A Comparison of Neurolept Anesthesia, Halothane Anesthesia and Epidural Anesthesia

Abstract: Intraoperative blood loss was measured during abdominal prostatectomies in 213 patients anesthetized with neurolept anesthesia, halothane anesthesia and epidural anesthesia. In 55 of these patients, postoperative bleeding was also measured. The average intraoperative blood loss with neurolept anesthesia was 8.2 ± 5 ml/min, with halothane anesthesia 6.6 ± 6.3 ml/min and with epidural anesthesia 3.8 ± 2.3 ml/min. The difference of blood loss in the epidural group and in the groups receiving general anesthesia is highly significant. Average systolic and diastolic blood pressures were lower during operation in the epidural group than in the other two groups. Statistical analyses failed, however, to show a significant correlation between blood pressures and blood loss in the individual patient. Thus, the ultimate explanation for the diminished bleeding associated with epidural anesthesia is not definitely ascertained. The average postoperative bleeding was not significantly different among the three anesthetic groups.